Dyeing textile materials of synthetic linear polyesters



United States, Patent Ofiice 3,3il,443 Patented Mar. 28, 1967 This invention relates to a process for dyeing synthetic linear polyester textile materials in brown to black shades.

It is known that colorfast shades can be produced by oxidation of aromatic amines on natural or synthetic materials. This method is particularly important for the production of deep black shades, for which p-aminoarylamines are chiefly used. This method of oxidation dyeing has also already been recommended for dyeing hydro phobic synthetic materials and, depending on the nature of the substrate to be dyed, various oxidizing agents, particularly those having organophilic character, i.e., oxidizing agents that are capable of penetrating into a hydrophobic fiber, have been proposed. Conventional oxidation dyeing of hydrophobic materials is attended however by various shortcomings which are attributable to the nature of the aromatic amine bases used. In order that the amine bases may have adequate afiinity for the hydrophobic substrate and may diffuse into the material to a sufiicien extent according to the prior art dyeing method, and in order that the deep brown and black shades which are so important coloristicaliy should be achieved, the amine bases must be polynuclear. Therefore p-aminodiarylamines are specially used. These compounds are however autoxidizable and often are stable in storage only in the form of their mineral acid salts. Bases liberated therefrom are only sparingly soluble in water and therefore can be used only in dispersed form. The sensitivity to oxidation and the insolubility of the amine bases often results in poor fastness to crocking of the dyeings obtained after oxidation. Attempts have been made to improve this by adding reducing agents to the dye liquor, by dispersing the amine bases and by appropriate aftertreatment of the developed dyeings.

It is the object of this invention to provide a process which permits the production of oxidation dyei-ngs on hydrophobic organic textile materials, particularly polyester textile materials, in a simple way without the said disadvantages.

We have found that dyeings of synthetic linear polyester textile materials by treatment with aminodiarylamines and oxidation of the amines absorbed by the textile material may be carried out advantageously by preparing the amine directly in the treatment liquor, i.e. in situ, by reductive cleavage of the water-soluble azo dye having the formula:

A denotes a radical of the benzene or naphthalene series,

B denotes a phenylene or naphthylene radical,

R denotes a hydrogen atom or a hydroxyl or alkoxyl R denotes a hydrogen atom or an alkyl, carboxylic acid,

hydroxyl or alkoxyl group, and

n denotes one of the numbers 1 and 2,

and treating the treated textile material with an oxidizing agent by a conventional method.

The dyes may be prepared by coupling a diazo component or tetrazo component which contains one or more Water-solubilizin rou s with a counlin com onent e P which is free from sulfonic groups and contains one or two hydroxy groups and/or amino groups necessary for coupling. The original diazo components contained in the dye do not take part in the formation of the dyeing after the cleavage. They serve for the introduction into the coupling component, via azo. coupling and reductive cleavage, of the amino group required for the oxidative dyeing, and also to impart temporary water-solubility and stability to autoxidation to the amine component to be oxidized. It is therefore preferred to use as diazo components simple readily accessible aminoarylsulfonic acids, such as aniline-Z-sulfonic acid, aniline-S-sulfonic acid, a-niline4-sulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, 1-naphthylamine-4-sulfonic acid, l-naphthylamine-S-sulfonic acid or 2-naphthylamine-4,8-disulfonic acid. Crude sulfonation mixtures of these arylamines may also be used with advantage. Coupling components having the general formula:

in which B, R and R have the above meanings are preferably secondary or tertiary amines of the benzene or naphthalene series, such as diphenylamine, N-phenyl-,8- naphthylamine, N-(p-tolyl)-a-naphthylamine or N-(3 carboxyphenyl)-B-naphthylamine. Phenols and naphthols or their alkyl ethers, such as 3-hydroxydiphenylamine, 3-ethoxy-4'-methyldiphenylamine, 3-methoxy-4- methyldiphenylamine, (4-methoxyphenyl) a naphthylamine and (4-ethoxyphenyl) a naphthylamine are also suitable.

Examples of reducing agents which are capable of cleaving the 2120 group under dyeing conditions are: netural or acid salts of hydrogen sulfide and of sulfurous acid or dithionous acid or compounds capable of splitting off these, and also glucose, hydrazine or arylihydrazines.

Reductive cleavage of the azo dyes, which are used in an amount of l to 20% (with reference to the weight of textile material) depending on the liquor ratio, and the treatment of the textile material in the reaction liquor may be carried out for example at 60 to 140 C. and pH values of 5 to 10, depending on the textile material to be dyed. The textile material may accordingly be treated according to the high temperature method at temperatures above C. or, preferably with the addition of carriers, at temperatures below 100 C. The reducing agents are advantageously used in a slight excess for the reductive cleavage. The weight of reducing agent is therefore from one half to double the weight of the dye used. The

textile material may be introduced into the reduction liquor at any time, i.e. prior to, during or not until after the reduction. Where the textile material is cloth, it may be padded with a concentrated liquor and. then steamed. The liquor ratio may therefore be chosen within a wide range, for example of from 4:1 to 50:1.

Whereas when dyeing polyester materials with disperse dyes in deep shades at temperatures below 100 C., an addition of carriers has always been made, it is possible by the process according to the present invention to obtain deep black dyeings having good fastness to light and very good resistance to contact heat by dyeing at temperatures below 100 C. and without the use of carriers.

Under these conditions, the new process is particularly suitable for dyeing polyester cellulose fiber union fabrics on covered jiggers, of polyester fiber woven or knitted fabrics in reel vats and for dyeing yarns of polyester fibers with polyester/ cellulose fiber union fabrics in a dyeing machine at atmospheric pressure.

The pretreated textile material is then treated in a second liquor with oxidizing agents in a conventional way, for example as described in US. patent specification No. 3,036,875 and in British patent specification No. 926,975. Quinones, quinonimines or quinonimide chlorides are particularly suitable as oxidizing agents.

Examples of quinones are naphthoquinone-(l,4), 2,3,5,6-tetrachlorobenzoquinone-( 1,4) 1,2-benzoquinone, 1,2-r1aphthoquinone and particularly benZoquinone-(l,4) and 2,5 -dichlorobenzoquinone-( 1,4)

The quinonimide chlorides are preferably those which are further substituted in the quinone nucleus and bear radicals such as halogen, for example chlorine, or alkoxyl. Examples are: 2,6-dichloromonochlorimidobenzoquinone or 2,6 dichloro l,4-bischlorimidobenzoquinone and the corresponding 2,5-dichloro derivatives, particularly 2,5-dichloro-1,4-bischlorimidobenzoquinone.

Examples of suitable synthetic linear polyester textile materials are preferably polyethylene glycol terephthalate in the form of fibers, filaments, threads, flock, woven fabrics and knitted fabrics.

In addition to the greater simplicity in the production of dyeings, the process according to this invention gives dyeings having greater depth of color by the carrier method than the prior art methods described above.

Finally it is possible by the process according to this invention to dye with black bases which could not be used in the prior art methods owing to low stability.

The invention is further illustrated by the following examples.

EXAMPLE 1 100 g. of polyethylene glycol terephthalate cloth is treated for one hour at 120 C. in a liquor which contains, in 4 liters of water, 8 g. of the compound obtained from 1-aminobenzene-4-sultonic acid by diazotization and coupling with 3-hydroxydiphenylamine, 4 g. of the reaction product of naphthalenesultonic acid and formaldehyde and 4 g. of sodium oxymethanesulfinate. The cloth is given an intermediate rinsing and then treated for one hour at boiling temperature in another liquor which contains, in 4 liters of water, g. of 2,5-dichloroquinone and l g. of the reaction product of 1 mole of sperm oil alcohol and 24 moles of ethylene oxide. Deep black dyeings are obtained which have very good light fastness, very good wet fastness properties and very good fastness to steampleating processes.

EXAMPLE 2 100 g. of polyethylene glycol terephthalate fibers is treated for ninety minutes at boiling temperature in a liquor which contains, in 2 liters of water, 10 g. of the compound obtained from l-aminobenzene-3-sulfonic acid .by diazotization and coupling with diphenylamine, 4 g. of sodium hydrosulfite and 6 g. of tricnlorobenzene in a finely divided form. The cloth is then rinsed for a short time and the dyeing is developed for thirty minutes at boiling temperature in another liquor which contains, in 2 liters of water, 8 g. of 2,5-dichloroquinone-1,4-dichlorimide in finely divided form. Deep black dyeings having very good fastness properties are obtained.

Similar results are obtained by using the compound obtained from l-amino-4-sulfonic acid by diazotization and coupling with phenyl-B-naphthylamine instead of the compound obtained from l-amino-4-sulfonic acid by diazotization and coupling with diphenylamine.

Equally valuable brown to black dyeings are obtained by using the following initial dyes and oxidizing agents:

Benzoquinone-(l, 4).

Napthoquiuone-(l, 4).

2, 3, 5, 6tetrachl0robenzoquinone-(l, 4).

l, 2-beuzoquinone.

1, Z-naphthoquinoue.

2, ti-dichloromonochlorimido-l, 4-benzoquiuone.

EXAMPLE 3 200 g. of polyethylene glycol terephthalate cloth is treated in a covered jigger with 2 liters of a liquor containing 12 g. of the azo dye l-aminobenzene-3-sulfonic aciddiphenylamine, 1.2 g. of isopropylnaphthalene sultonate, 10 g. of sodium carbonate and 25 g. of sodium dithionite. The treatment is commenced at C. and the temperature of the liquor is raised to boiling point during the course of thirty minutes and kept at the boiling temperature for one hour. Then the cloth is rinsed for about ten mintues with hot water at about C. and the black dyeing is developed by heating for one hour at boiling temperature with a dispersion of 24 g. of 2,5-dichloroquinone in 2 liters of water.

The cloth is rinsed with hot water and the dyeing is reductively purified in a solution of 3 g./l. of sodium hydroxide and 6 g./l. of sodium dithionite for twenty minutes at C.

A block dyeing is obtained having very good fastness to light and excellent thermal resistance.

EXAMPLE 4 400 g. of polyethylene glycol terephthalate yarn is treated in an open dyeing machine with 10 liters of a liquor containing 32 g. of the dye l-arninobenzene-Ii-sulfonic aciddiphenylamine, S g. of isopropylnaphthalene sulfonate, 20 g. of sodium carbonate and 50 g. of sodium dithionite. The treatment is commenced at 50 C., the temperature is raised during the course of thirty minutes to to 98 C. and the liquor kept at this temperature for one hour. The yarn is given a thorough intermediate rinsing at 60 C. and the black dyeing is developed by heating for one hour at boiling temperature in a liquor containing 50 g. of 2,5-dichloroquinone-1,4-dichlorimide. The dyed yarn is rinsed well with hot water at 60 C. and subjected to reductive purification at 70 C.

We claim:

1. In a process for dyeing synthetic linear polyester textile material by treatment of said material with a primary aromatic amine in a first liquor and oxidation of the amine absorbed by the textile material in a second liquor, the improvement which comprises preparing the amine in situ in said first treatment liquor by reductive cleavage of the azo group of an azo dye having the general formula:

in which:

A represents a member selected from the group consisting of phenylene and naphthylene,

B represents a member selected from the group consisting of phenylene and naphthylene,

R represents a member selected from the group consisting of a hydrogen atom, hydroxy, methoxy and ethoXy,

R represents a member selected from the group consisting of hydrogen, methyl, carboxy, methoxy and ethoxy and n represents one of the integers 1 and 2,

and subjecting the textile material which has been treated in said first liquor to said oxidation in said second liquor.

2. A process according to claim 1 which comprises using as reducing agent for the reductive cleavage an inorganic salt of an acid selected from the group consisting of hydrogen sulfide, dithionous acid, sulfurous acid and a compound capable of splitting off said reducing agent.

3. A process according to claim 1 which comprises using using as the oxidizing agent a member selected from the class consisting of 1,4-benzoquinone, 2,5-dichlorobenzoquinone (l,4) and 2,5 dichloro 1,4 bischlorimidobenzoquinone.

4. In a process for dyeing synthetic linear polyester textile material by treatment of said material with a primary aromatic amine in a first liquor and oxidation of the amine absorbed by the textile material in a second 6 liquor, the improvement which comprises preparing the amine in situ in said first treatment liquor by reductive cleavage of the azo group of an azo dye having the formula:

with sodium hydrosulfite and subjecting the textile material which has been treated in said first liquor to said oxidation in said second liquor.

References Cited by the Examiner UNITED STATES PATENTS 2,926,060 2/1960 Lehmann et a1. 832 X 3,036,875 5/1962 Schlack et al. 8-32 FOREIGN PATENTS 1,145,138 3/1963 Germany. 

1. IN A PROCESS FOR DYEING SYNTHETIC LINEAR POLYESTER TEXTILE MATERIAL BY TREATMENT OF SAID MATERIAL WITH A PRIMARY AROMATIC AMINE IN A FIRST LIQUOR AND OXIDATION OF THE AMINE ABSORBED BY THE TEXTILE MATERIAL IN A SECOND LIQUOR, THE IMPROVEMENT WHICH COMPRISES PREPARING THE AMINE IN SITU IN SAID FIRST TREATMENT LIQUOR BY REDUCTIVE CLEAVAGE OF THE AZO GROUP OF AN AZO DYE HAVING THE GENERAL FORMULA: (HO3S)N-A-N=N-B(-R1)-NH-(PHENYLENE)-R2 IN WHICH: 